Intervertebral implant and installation tool

ABSTRACT

An intervertebral implant ( 25 ), an installation tool ( 500 ), and related methods are provided for ensuring a minimum distance between two vertebrae. The implant ( 25 ) can comprise a pair of opposing body portions ( 1, 2 ) and an expansion component. The expansion component can rotate relative to the body portions ( 1, 2 ) in order to urge a head portion ( 4 ) thereof against one or more inclined contact surfaces of at least one of the body portions ( 1, 2 ). In this manner, the body portions ( 1, 2 ) can be separated, thereby increasing a height of the implant ( 25 ). The installation tool ( 500 ) can comprise a plurality of components that can be moved relative to each other to facilitate expansion or contraction of the implant ( 25 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority benefit under 35 U.S.C. §119(a) fromSpanish Patent Application No. ES 200801551, filed May 26, 2008, andunder 35 U.S.C. §119(e) from U.S. Provisional Application Ser. No.61/176,460, filed on May 7, 2009, the entireties of the disclosures ofeach of which are hereby expressly incorporated herein by reference.

BACKGROUND

1. Field of the Inventions

The present inventions relate to medical devices and, more particularly,to an intervertebral implant and an installation tool.

2. Description of the Related Art

The human spine is a flexible weight bearing column formed from aplurality of bones called vertebrae. There are thirty-three vertebrae,which can be grouped into one of five regions (cervical, thoracic,lumbar, sacral, and coccygeal). Moving down the spine, there aregenerally seven cervical vertebrae, twelve thoracic vertebrae, fivelumbar vertebrae, five sacral vertebrae, and four coccygeal vertebrae.The vertebrae of the cervical, thoracic, and lumbar regions of the spineare typically separate throughout the life of an individual. Incontrast, the vertebra of the sacral and coccygeal regions in an adultare fused to form two bones, the five sacral vertebrae which form thesacrum and the four coccygeal vertebrae which form the coccyx.

In general, each vertebra contains an anterior, solid segment or bodyand a posterior segment or arch. The arch is generally formed of twopedicles and two laminae, supporting seven processes—four articular, twotransverse, and one spinous. There are exceptions to these generalcharacteristics of a vertebra. For example, the first cervical vertebra(atlas vertebra) has neither a body nor spinous process. In addition,the second cervical vertebra (axis vertebra) has an odontoid process,which is a strong, prominent process, shaped like a tooth, risingperpendicularly from the upper surface of the body of the axis vertebra.Further details regarding the construction of the spine may be found insuch common references as Gray's Anatomy, Crown Publishers, Inc., 1977,pp. 33-54, which is herein incorporated by reference.

The human vertebrae and associated connective elements are subjected toa variety of diseases and conditions which cause pain and disability.Among these diseases and conditions are spondylosis, spondylolisthesis,vertebral instability, spinal stenosis and degenerated, herniated, ordegenerated and herniated intervertebral discs. Additionally, thevertebrae and associated connective elements are subject to injuries,including fractures and torn ligaments and surgical manipulations,including laminectomies.

The pain and disability related to the diseases and conditions oftenresult from the displacement of all or part of a vertebra from theremainder of the vertebral column. Over the past two decades, a varietyof methods have been developed to restore the displaced vertebra totheir normal position and to fix them within the vertebral column.Spinal fusion is one such method. In spinal fusion, one or more of thevertebra of the spine are united together (“fused”) so that motion nolonger occurs between them. Thus, spinal fusion is the process by whichthe damaged disc is replaced and the spacing between the vertebrae isrestored, thereby eliminating the instability and removing the pressureon neurological elements that cause pain.

Spinal fusion can be accomplished by providing an intervertebral implantbetween adjacent vertebrae to recreate the natural intervertebralspacing between adjacent vertebrae. Once the implant is inserted intothe intervertebral space, osteogenic substances, such as autogenous bonegraft or bone allograft, can be strategically implanted adjacent theimplant to prompt bone ingrowth in the intervertebral space. The boneingrowth promotes long-term fixation of the adjacent vertebrae. Variousposterior fixation devices (e.g., fixation rods, screws etc.) can alsobe utilize to provide additional stabilization during the fusionprocess.

Recently, intervertebral implants have been developed that allow thesurgeon to adjust the height of the intervertebral implant. Thisprovides an ability to intra-operatively tailor the intervertebralimplant height to match the natural spacing between the vertebrae. Thisreduces the number of sizes that the hospital must keep on hand to matchthe variable anatomy of the patients.

In many of these adjustable intervertebral implants, the height of theintervertebral implant is adjusted by expanding an actuation mechanismthrough rotation of a member of the actuation mechanism. In someintervertebral implants, the actuation mechanism is a screw or threadedportion that is rotated in order to cause opposing plates of the implantto move apart. In other implants, the actuation mechanism is a helicalbody that is counter-rotated to cause the body to increase in diameterand expand thereby.

Furthermore, notwithstanding the variety of efforts in the prior artdescribed above, these intervertebral implants and techniques areassociated with another disadvantage. In particular, these techniquestypically involve an open surgical procedure, which results higher cost,lengthy in-patient hospital stays and the pain associated with openprocedures.

Therefore, there remains a need in the art for an improvedintervertebral implant. Preferably, the implant is implantable through aminimally invasive procedure. Further, such devices are preferably easyto implant and deploy in such a narrow space and opening while providingadjustability and responsiveness to the clinician.

SUMMARY

While using minimally invasive procedures to deploy an intervertebralprostheses is generally advantageous, such procedures do have thedisadvantages of generally requiring the device to be passed through arelatively small diameter passage or tube. In addition, deployment toolstypically must also be deployed through the small diameter passage ortube.

As described, a typical intervertebral implant includes expansionmembers that are deployed to a fixed position and dimension. In thisregard, according to at least one of the embodiments disclosed herein isthe realization that the deployed implant is completely rigid, which isunnatural and affects the comfort of the patient's movements. Inaddition, many prior art intervertebral prostheses are not adjustable inheight. In other words, a surgeon cannot precisely set the spacingbetween vertebrae secured by the implant.

Furthermore, after deploying the implant, extraction or positionaladjustments using an minimally invasive procedures are potentiallydangerous and can damage the tissue of the patient. These disadvantagescan cause neuritis, among other complications. Nevertheless, it isgenerally common for a surgeon to have to relocate or remove the implantbecause the surgeon often has no means of knowing exactly where theimplant is located.

Therefore, in accordance with at least one of the embodiments disclosedherein, there is provided an implant for use of intervertebral endoscopethat overcomes the aforementioned drawbacks. For example, the implantcan even be adjustable in height once installed, which allows theimplant to be extracted or adjusted in the event of incorrect placement.Further, in some embodiments, the implant can allow for a degree ofelasticity in the minimum separation of vertebrae.

More specifically, some embodiments disclosed herein comprise anintervertebral implant that can maintain a minimum distance between twojoint vertebrae. The implant can comprise two expandable body portionsand an expansion component. The two body portions can each have ageneral shape of a wedge. In some embodiments, each body portion cancomprise a first surface configured to contact a vertebra and a secondsurface. In some embodiments, the second surface can be orientedobliquely relative to the first surface. Further, the second surface canbe an inner surface that is inclined or slanted relative to the firstsurface.

In addition, the second surface of each body portion can be configuredto allow the two body portions to be introduced against each other. Inthis regard, the body portions can comprise one or more structuralcomponents that allow the body portions to be interconnected orreleasably mated. For example, each of the body portions can compriseone or more offset structures that allow the second surfaces of the bodyportions to traverse each other, such as by an interlinked orinterweaving configuration. In such an embodiment, the second surfacescan be defined by top surfaces or planes defined by one or more raisedstructures. Further, the body portions can define one or more gaps orspaces adjacent to the one or more raised structures. In this regard,when the body portions are interlinked, one or more raised structures ofone of the body portions can be received into one or more gaps or spacesof the other body portion such that the body portions can be at leastpartially interlinked with the second surfaces traversing each other.

Furthermore, in accordance with some embodiments, the expansioncomponent of the implant can engage the body portions to facilitateseparation of the body portions. In this regard, the expansion componentof the implant can move along a longitudinal axis of the implant andcause one or both of the body portions to move in a direction transverseto the longitudinal axis of the implant so as to cause the body portionsto move apart from each other. For example, in some embodiments, theexpansion component can comprise a rounded or spheroid-shaped area thatcan engage or contact the second surface of the body portions. Incertain embodiments, the expansion component can contact inclined secondsurfaces of the body portions to spread or urge the body portions apart.

The expansion component can comprise a head portion and a ram member.The head portion can be shaped as a spheroid, an ellipsoid, a cone, oras a pyramid having three or more sides, such as a triangular or squarepyramid. Further, the head portion and the ram member can be formedseparately from each other as individual components or can be formed asa unitary or monolithic piece. Accordingly, in an embodiment, the rammember can contact the head portion, and advancement of the ram memberalong the longitudinal axis can cause the head portion to move with therain member relative to the body portions of the implant on therebyforcing the body portions apart.

In embodiments wherein the head portion of the expansion component isformed separately from the ram member of the expansion component, theimplant can also comprise a confinement casing. The confinement casingcan be configured to limit and/or prevent the movement of the headportion in a direction other than along the longitudinal axis of theimplant. Accordingly, movement of the head portion caused by contactfrom the ram member can be confined to movement along the longitudinalaxis. In this regard, motion of the ram member can be transferredefficiently and effectively to the head portion to cause the bodyportions to separate and cause a change in the height of the implant.Thus, in embodiments utilizing the confinement casing, the casing canprevent the head portion of the expansion component from exiting theactivity area or space defined between the body portions.

In some embodiments, the confinement casing can comprise a channel. Thechannel can be configured to at least partially receive the ram memberof the expansion component. For example, the channel can include one ormore retention structures that can engage corresponding retentionstructures of the ram member. In such an embodiment, the retentionstructures of the channel can comprise one or more threads thatthreadably connect with threads of the ram member. In this regard, theengagement of retention structures of the channel with the retentionstructures of the rain member can not only provide an unlimitedpossibility of implant heights, but can also maintain the implant heightagainst forces seeking to collapse the body portions into each other.

Additionally, the confinement casing can comprise a cap or lid elementlocated on an end that is opposite the channel. For example, theconfinement casing can be an elongate member with a first end and asecond end. The channel can be formed in the first end of theconfinement casing and the lid component can be disposed at the secondend of the confinement casing. Moreover, the confinement casing cancomprise a pair of sidewalls extending intermediate the lid componentand the first end of the confinement casing. The pair of sidewalls candefine a compartment therebetween into which the body portions can be atleast partially received. In this regard, the compartment can be definedby the sidewalls, the lid component, and an end face of the channel.Accordingly, in such an embodiment, the expansion component can bedisposed through the channel and extend into the compartment such thatat least the head portion of the expansion component is disposed betweenbody portions seated within the compartment.

One of the unique advantages of some embodiments is that the compartmentof the confinement casing can be configured to guide or limit relativemovement between the body portions. For example, the pair of sidewallspositioned along the sides of the compartment can prevent side-to-siderelative motion between the body portions and guide vertical expansiveor contractive relative movement between the body portions. Further, thelid component can prevent end-to-end relative motion between the bodyportions while also guiding the vertical expansive or contractiverelative movement between the body portions. This advantageousconfiguration can thereby facilitate proper relative movement of thebody portions and minimize the possibility of misalignment ordislocation of the body portions from their vertical relative movement.

The separation or height of the implant can be defined by externalsurfaces of the body portions. In turn, the separation between theexternal surfaces depends on the degree of penetration or axialdisplacement of the head portion which can be in contact with the secondsurfaces of the body portions. Further, the degree of penetration oraxial displacement of the head portion between the body portions dependson the movement or progress of the ram member.

In accordance with some embodiments, the implant can comprise aheight-limiting component. The height-limiting component can limit therelative motion between the body portions. For example, theheight-limiting component can comprise one or more recesses orprojections on at least one side of one or both of the body portions.The recesses or projections of the body portion(s) can engagecorresponding projections or recesses formed on the confinement casing.For example, in an embodiment, the body portions can each comprise oneor more recesses that engage corresponding protrusions formed along thesidewalls of the confinement casing. In use, such an embodiment can havea predetermined maximum implant height that is reached when theprotrusions of the confinement casings engage an end of the recesses ofthe body portions, thus preventing further relative movement between thebody portions.

As noted above, in some embodiments, the body portions can comprisestructural components that allow the body portions to interlink. Inaccordance with such an embodiment, the structural components can limitone or more degrees of movement between the body portions. As such, whenthe body portions are interlinked, vertical movement can be permittedwhile horizontal movement is restricted. The structural components ofthe body portions can have a dual function. First, they can guiderelative motion between the body portions. Second, they can ensure aminimum implant height or distance between body portions. Further, thestructural components can form an internal wedge structure against whichthe head portion can act, allowing the implant height to be varied alonga continuum of positions. Additionally, it is contemplated that theimplant height can be varied along a plurality of discrete positions.

One of the unique advantages of embodiments of the implant is that theimplant can avoid locking and can be easily adjustable and reversible.Reversibility greatly facilitates the placement of the implant.Moreover, the head portion can be used as a shock absorber. For example,the head portion can be made of a material that presents certain elasticproperties, such as Teflon or nylon, which allows a degree of impactabsorption, without compromising too much in maintaining the minimumseparation between vertebrae.

In some embodiments, the implant can provide an elastic recovery elementthat interconnects the body portions. The elastic recovery element canbe configured as an elastic mesh material or a rubber or elastic toroid,for example. In the event of a dislocation of the body portions relativeto each other, the elastic recovery element can facilitate therelocation or return of the body portions to the pre-dislocationposition.

For example, in an embodiment, the elastic recovery element caninterconnect the body portions in a vertical direction and interact withthe expansion component. In this regard, such an elastic recoveryelement can provide a vertical contracting force against the verticalexpansion or separation of the body portions. In such an embodiment, theelastic recovery element can be placed in the space between bodyportions. In other embodiments, the expansion component can beconfigured to fit within the channel or compartment of the confinementcasing.

In yet another embodiment, an intervertebral implant is provided forensuring a minimum distance between two vertebrae. The implant cancomprise a pair of body portions and an expansion component. The pair ofbody portions can each comprise an external surface and a contactsurface that is oriented obliquely relative to the external surface. Thebody portions can each comprise at least one raised structure and atleast one gap positioned adjacent to the raised structure. The raisedstructure can define a top surface that forms at least a portion of thecontact surface of the body portion. The raised structures of each bodyportion and be insertable into the respective gaps of the other bodyportion such that the contact surfaces thereof define an internal wedgestructure between the body portions.

Further, the expansion component can comprise a head portion and a rammember. The expansion component can be at least partially insertablebetween the body portions with the head portion positioned against thecontact surfaces of the body portions. The ram member can be operativeto urge the head portion against the contact surfaces such that movementof the head portion against the internal wedge structure causes the bodyportions to separate thereby increasing a height of the implant. In someembodiments, the expansion component can comprise one or more engagementstructures for engaging with an expansion tool for rotating theexpansion component. Further, the expansion component can comprise athreaded recess for engaging with the expansion tool for maintaining theexpansion component in a given axial position relative to the toolduring rotation of the expansion component.

In such an embodiment, the implant can further comprise a confinementcasing to prevent the movement of the head portion of the expansioncomponent in a direction transverse to a longitudinal axis of theimplant. The confinement casing can comprise a channel configured toreceive at least a portion of the ram member therein. Further, theconfinement casing can comprise an elongate body having a lid at an endlocated distal to the channel and a compartment interposed between thelid and the channel. The compartment can be at least partially definedby a pair of sidewalls extending intermediate the lid and an end of thechannel. The compartment can be configured to at least partially receivethe body portions therein. Furthermore, the channel can be threaded, andthe ram member can comprise at least one thread extending along anexterior surface thereof. In this regard, the ram member can beconfigured to threadingly engage the channel of the confinement casing.The casing can also comprise one or more engagement surfaces disposed ata proximal end of the casing, and the engagement surfaces can beconfigured to engage with an expansion tool for maintaining a rotationalorientation of the implant with respect to at least a portion of theexpansion tool.

Moreover, the ram member can move along a direction parallel to alongitudinal axis of the implant to urge the head portion against thecontact surfaces of the body portions.

Additionally, some embodiments can comprise a recovery element extendingbetween the body portions. The recovery element can be a mesh withelastic properties. For example, the recovery element can at leastpartially surround the body portions. Further, the recovery element cancomprise an elastic rubber band.

In some embodiments, the implant can also comprise an expansion limitingsystem for limiting the expansion of the implant. The expansion limitingsystem can comprise a projection formed on one body portion thatinterferes with an end cap formed on the other body portion for limitingrelative vertical motion between the body portions.

Further, the external surfaces of the body portions comprise one or moreprojections for promoting osseointegration of the surfaces with adjacentvertebrae.

In yet another embodiment, an intervertebral implant is provided forensuring a minimum distance between two vertebrae. The implant cancomprise a first body portion, a second body portion, and an expansioncomponent. The first body portion can comprise a first external surfaceand a first contact surface. The first body portion can comprise atleast one raised structure and at least one gap positioned adjacent tothe raised structure. The second body portion can comprise a secondexternal surface and a second contact surface that is oriented obliquelyrelative to the first external surface. The second body portion cancomprise at least one raised structure and at least one gap positionedadjacent to the raised structure. The raised structure can define a topsurface that forms at least a portion of the second contact surface ofthe body portion. In this regard, each raised structure of the firstbody portion can be insertable into the respective gap of the secondbody portion and each raised structure of the second body portion can beinsertable into the respective gap of the first body portion such thatthe contact surfaces thereof define an internal wedge structure betweenthe first body portion and the second body portion.

Further, the expansion component can comprise a head portion and a rammember. The expansion component can be at least partially insertablebetween the first body portion and the second body portion with the headportion positioned against the first and second contact surfaces. Theram member can be operative to urge the head portion against the firstand second contact surfaces such that movement of the head portionagainst the internal wedge structure causes the first body portion toseparate from the second body portion thereby increasing a height of theimplant. In other embodiments, the expansion component can comprise athreaded recess for engaging with an expansion tool for maintaining theexpansion component in a given axial position relative to the toolduring rotation of the expansion component.

In some embodiments, the first contact surface of the first body portioncan be oriented obliquely relative to the first external surface.Further, the head portion of the expansion component can be formedseparately from the ram member. Furthermore, the head portion of theexpansion component can comprise a generally spherical member. The headportion of the expansion component can be elastically deformable forproviding a shock absorption capability to the implant. For example, thehead portion is fabricated from one of nylon and Teflon. In addition,some embodiments can be implemented in which the head portion comprisesat least one cavity for enhancing the shock absorption capability of theimplant.

In other embodiments, the implant can comprise a confinement casing. Theconfinement casing can comprise a channel, a lid, and a compartmentextending intermediate the channel and the lid. The channel can beconfigured to receive at least a portion of the ram member therein. Thecompartment can be at least partially defined by a pair of sidewallsextending intermediate the lid and an end of the channel. Thecompartment can be configured to at least partially receive the bodyportions therein. The confinement casing can be configured to align thebody portions in a vertical direction and prevent movement of theexpansion component in a direction transverse to a longitudinal axis ofthe implant.

In some embodiments, the channel can be threaded and the ram member cancomprise at least one thread extending along an exterior surfacethereof. In this regard, the ram member can be configured to threadinglyengage the channel of the confinement casing. Further, the casing cancomprise one or more engagement surfaces disposed at a proximal end ofthe casing. The engagement surfaces can be configured to engage with anexpansion tool for maintaining a rotational orientation of the implantwith respect to at least a portion of the expansion tool.

In accordance with yet another embodiment, an installation tool isprovided for installing an implant. The tool can comprise a handlemember, a first rotating member, and a second rotating member. Thehandle member can have a gripping component and an elongate tubularcomponent extending from the gripping component. The tubular componentcan have a hollow bore and an engagement portion disposed at a distalend thereof. The engagement portion can have one or more protrusions forengaging at least a portion of a proximal end of an intervertebralimplant to maintain a rotational orientation of the implant relative tothe tubular component.

The first rotating member can have a first knob and an actuationcomponent extending from the first knob. The actuation component canhave a hollow bore and a rotational connector disposed at a distal endthereof. The actuation component can be configured to fit within thehollow bore of the tubular component of the handle member with therotational connector being positioned adjacent to the engagement portionof the tubular component for engaging an expansion component of theimplant for rotating the expansion component to expand or contract theimplant.

Further, the second rotating member can have a second knob and aretention component extending from the second knob. The retentioncomponent can have a fastening portion disposed at a distal end thereof.The retention component can be configured to fit within the hollow boreof the actuation component of the first rotating member with theretention component being positioned adjacent to the rotationalconnector of the actuation component of the first rotational member forengaging the expansion component of the implant for maintaining an axialposition of the implant relative to the handle member during rotation ofthe expansion component.

In some embodiments, the engagement portion of the tubular component ofthe handle member can comprise a pair of protrusions. Further, the pairof protrusions can be disposed on opposing sides of the tubularcomponent with the implant being insertable therebetween. The rotationalconnector of the actuation component of the first rotating member canalso comprise a pair of linear protrusions configured to be received ina slot of the expansion component of the implant. The tubular componentof the actuation component and the retention component can also comprisegenerally cylindrical outer profiles. The retention component of thesecond rotating member can also be configured to draw the expansioncomponent of the implant toward the actuation component of the firstrotational member as the retention component engages the ram member.Furthermore, the fastening portion of the retention component can bethreaded for threadably engaging the ram member of the implant.

In accordance with yet another embodiment, a method of implanting anexpandable intervertebral implant is provided that can comprise:dilating a pathway to an intervertebral disc; removing the nucleus of anintervertebral disc to define a disc cavity; scraping vertebral endplates from within the disc cavity; and deploying an intervertebralimplant in the disc cavity.

In some implementations of the method, the step of dilating cancomprise: inserting a needle into the intervertebral disc; inserting afirst dilator over the needle into the intervertebral disc; removing theneedle; inserting a second dilator over the first dilator into theintervertebral disc; and removing the first dilator. Further, the methodcan comprise: inserting a first working sleeve over the second dilatorto adjacent the intervertebral space; and removing the second dilator.Furthermore, the method can comprise: inserting a second working sleeveover the first working sleeve to adjacent the intervertebral space; andremoving the first working sleeve.

Additionally, the step of removing the nucleus can comprise using atrephine tool. The step of removing the nucleus can also comprise usinga punch tool. In some embodiments, the method can comprise drilling ahole into the intervertebral disc after dilation. In this regard, thestep of drilling can comprise forming a hole in the intervertebral disc.The step of drilling can also comprise forming a hole in the vertebralend plates. Further, in some embodiments, the scraping step can compriseinserting a rasp into the intervertebral disc to scrape the vertebralend plates from within the disc cavity. Furthermore, the step ofdeploying the implant can comprise expanding the implant fromapproximately 9 mm to approximately 12.5 mm in height.

BRIEF DESCRIPTION OF THE DRAWINGS

The abovementioned and other features of the inventions disclosed hereinare described below with reference to the drawings of the preferredembodiments. The illustrated embodiments are intended to illustrate, butnot to limit the inventions. The drawings contain the following figures:

FIG. 1 is a perspective view of an intervertebral implant, according toan embodiment of the present inventions.

FIG. 2 is an exploded perspective view of the implant of FIG. 1 and anexpansion tool for adjusting a height of the implant, according to anembodiment.

FIG. 3 is a perspective view of the implant and the tool of FIG. 2wherein the implant is in assembled state.

FIG. 4 is a perspective view of body portions of the implant of FIG. 1,according to an embodiment.

FIG. 5 is a side cross-sectional view of the implant and the tool ofFIG. 3 wherein the tool is actuating an expansion component of theimplant to increase the implant height, according to an embodiment.

FIG. 6 is a side cross-sectional view of the implant and the tool ofFIG. 3 wherein the implant is in a collapsed state, according to anembodiment.

FIG. 7 is a perspective view of an intervertebral implant and anexpansion tool, according to another embodiment.

FIG. 8 is an exploded perspective view of the implant and tool of FIG.7.

FIG. 9 is a rear perspective view of the implant and the tool of FIG. 7,wherein the implant is in an expanded state.

FIG. 10 is a front perspective view of the implant and tool of FIG. 7,wherein the implant is in the expanded state.

FIG. 11 is a perspective cross-sectional view of the implant and tool ofFIG. 7, wherein the implant is in the expanded state.

FIG. 12 is a perspective view of body portions of an intervertebralimplant, wherein the body portions are in a collapsed state, inaccordance with an embodiment.

FIG. 13 is a perspective view of the body portions of FIG. 12 havingbeen expanded to an expanded state by actuation of a head portion of anexpansion component of the implant, according to an embodiment.

FIG. 14 is a perspective view of a confinement casing of anintervertebral implant, according to an embodiment.

FIG. 15 is a front perspective view of a first body portion of anintervertebral implant, according to an embodiment.

FIG. 16 is a rear perspective view of the first body portion of FIG. 15.

FIG. 17 is a top view of the first body portion of FIG. 15.

FIG. 18 is a rear perspective view of a second body portion of anintervertebral implant, according to an embodiment.

FIG. 19 is a front perspective view of the second body portion of FIG.18.

FIG. 20 is top view of the second body portion of FIG. 18.

FIG. 21 is a front perspective view of yet another embodiment of anintervertebral implant, wherein the implant is in a collapsed state.

FIG. 22 is a front perspective view of a first body portion of theintervertebral implant of FIG. 21.

FIG. 23 is a partial cross-sectional perspective view of theintervertebral implant of FIG. 21.

FIG. 24 is a perspective view of a confinement casing of theintervertebral implant of FIG. 21, according to an embodiment.

FIG. 25 is a perspective view of the intervertebral implant of FIG. 21,wherein the implant is in an expanded state.

FIG. 26 is a perspective view of first and second body portions and anexpansion component of the intervertebral implant of FIG. 25, accordingto an embodiment.

FIG. 27 is a rear perspective view of first and second body portionsbeing hingedly interconnected, according to an embodiment.

FIG. 28 is a side view of the first and second body portions of FIG. 27.

FIG. 29 is a perspective view of an expansion component, according toanother embodiment.

FIG. 30 is a front perspective view of a first body portion, accordingto an embodiment.

FIG. 31 is a front perspective view of a second body portion, accordingto an embodiment.

FIG. 32 is a bottom perspective view of the second body portion of FIG.31.

FIG. 33 is a perspective view of an installation tool and anintervertebral implant seated in a deployment portion of the tool,according to embodiments thereof.

FIG. 34 is a perspective view of the installation tool shown in FIG. 33.

FIG. 35 is a perspective view of first and second adjustment portions ofthe tool shown in FIG. 33, according to an embodiment.

FIG. 36 is a perspective view of the second adjustment portion of thetool shown in FIG. 33, according to an embodiment.

FIG. 37 is a cross-sectional top view of the installation tool and theintervertebral implant shown in FIG. 33 illustrating engagement betweenthe tool and the implant, according to an embodiment.

FIG. 38 is a perspective view of the implant shown in FIG. 33.

FIG. 39 is an exploded view of the implant shown in FIG. 38, accordingto an embodiment.

FIG. 40 is a cross-sectional side view of the installation tool and theintervertebral implant shown in FIG. 33 illustrating engagement betweenthe tool and the implant, wherein the implant is a collapsed state andportions of the implant and the tool are rotated 90° relative to thatshown in FIG. 37.

FIG. 41 is a cross-sectional side view of the installation tool and theintervertebral implant shown in FIG. 33, wherein the implant is in anexpanded state.

FIG. 42 is a top view of the installation tool and the intervertebralimplant shown in FIG. 33.

FIG. 43 is a rear perspective view of the intervertebral implant and adistal engagement portion of the second adjustment portion of theinstallation tool, according to an embodiment.

FIG. 44 is a rear perspective view of an expansion component of theintervertebral implant, according to an embodiment.

FIG. 45 is a front perspective view of the expansion component shown inFIG. 44.

FIG. 46 is a bottom perspective view of a first body portion of theintervertebral implant, according to an embodiment.

FIG. 47 is a top perspective view of a second body portion of theintervertebral implant, according to an embodiment.

FIG. 48 is a cross sectional top view of the intervertebral implantshown in FIG. 38.

FIG. 49 illustrates a longitudinal cross-sectional view and an end viewof a rasp tool in an unexpanded configuration, according to anembodiment.

FIG. 50 illustrates a longitudinal cross-sectional view and an end viewof the rasp tool shown in FIG. 49, wherein the rasp tool is in anexpanded configuration, according to an embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with certain embodiments disclosed herein, an improvedintervertebral implant is provided that allows the clinician to insertthe intervertebral implant through a minimally invasive procedure. Forexample, in one embodiment, one or more intervertebral implants can beinserted percutaneously to reduce trauma to the patient and therebyenhance recovery and improve overall results of the surgery. Byminimally invasive, Applicant means a procedure performed percutaneouslythrough an access device in contrast to a typically more invasive opensurgical procedure. Such access devices typically provide an elongatedpassage that extends percutaneously through the patient to the targetsite. Examples of such access devices include, but are not limited to,endoscopes and the devices described in U.S. Patent Application Nos.2006-0030872 and 2005-0256525 and U.S. Pat. Nos. 6,793,656 and7,223,278, the entirety of these patent applications and patents arehereby incorporated by reference herein.

In some embodiments, the intervertebral implant can ensure a minimumdistance between adjacent vertebrae (a function that a healthyindividual's intervertebral disc can performs naturally). Becauseembodiments of the intervertebral implant can be implemented throughminimally invasive procedures, such embodiments of the implant can passthrough the interior of an access device (usually a tube having adiameter of between 5-9 mm), and then expanded inside the patient.Further, the tools for deploying the implant should also be suitable forminimally invasive procedures.

Certain embodiments disclosed herein are discussed in the context of anintervertebral implant and spinal fusion because of the applicabilityand usefulness in such a field. The device can be used for fusion, forexample, by expanding the device to an appropriate intervertebral heightand then inserting bone morphogenetic protein (BMP) or graft material.As such, various embodiments can be used to properly space adjacentvertebrae in situations where a disc has ruptured or otherwise beendamaged. “Adjacent” vertebrae can include those originally separatedonly by a disc or those that are separated by intermediate vertebra anddiscs. Such embodiments can therefore tend to recreate proper discheight and spinal curvature as required in order to restore normalanatomical locations and distances. However, it is contemplated that theteachings and embodiments disclosed herein can be beneficiallyimplemented in a variety of other operational settings, for spinalsurgery and otherwise.

In addition, certain embodiments of the device can also be used toprovide dynamic intervertebral support. For example, the device can beused to maintain an intervertebral height without fusion and withoutdisc degeneration to the adjacent levels. As discussed further herein,certain components of the device can be configured to resilientlysupport adjacent vertebrae. In some embodiments, the device can compriseone or more components fabricated from a resilient or elastic material.The device can thus be configured to deflect within a desired range ofintervertebral heights in order to provide dynamic spacing and supportbetween adjacent vertebrae.

It is contemplated that the implant can be used as an interbody orintervertebral device. Further, the implant can be used as a tool toexpand an intervertebral space or bone in order to fill the space orbone with a cement; in such cases, the implant can be removed or left inonce the cement is placed. Furthermore, the implant can also be used asa tool to predilate disc space. Finally, the implant can also beintroduced into the disc space anteriorly in an anterior lumbarinterbody fusion (ALIF) procedure, posterior in an posterior lumbarinterbody fusion (PILF) or postero lateral interbody fusion, fromextreme lateral position in an extreme lateral interbody fusionprocedure, and transforaminal lumbar interbody fusion (TLIF), to name afew. Although the implant is primarily described herein as being used toexpand in a vertical direction, it can also be implanted to expand in ahorizontal direction in order to increase stability and/or increasesurface area between adjacent vertebral bodies. Therefore, it iscontemplated that a number of advantages can be realized utilizingvarious embodiments disclosed herein. For example, as will be apparentfrom the disclosure, no external distraction of the spine is necessary.Further, no distraction device is required in order to install variousembodiments disclosed herein. In this regard, embodiments of the implantcan enable sufficient distraction of adjacent vertebra in order toproperly restore disc height or to use the implant as a vertebral bodyreplacement. Thus, normal anatomical locations, positions, and distancescan be restored and preserved utilizing many of the embodimentsdisclosed herein.

Referring now to the figures, illustrations of certain embodiments areprovided for the purpose of illustrating certain embodiments of thepresent inventions and not for the purpose of limiting the same.

In this regard, FIGS. 1-6 illustrate an embodiment of an intervertebralimplant 25 configured to be implanted using a minimally invasiveprocedure. Further, FIGS. 2, 3, 5 and 6 show tools that allow for manualcontrol in minimally invasive procedure. Thus, it is contemplated thatembodiments disclosed herein can pass through a cannula or other type ofaccess device to be implanted in the spine of a patient.

Referring now to FIGS. 1-6, an embodiment of an intervertebral implant25 is shown. The implant 25 can comprise the first and second bodyportions 1, 2. The first and second body portions 1, 2 can compriserespective upper and lower external surfaces that are configured to abutagainst adjacent vertebrae (or intervening structure) when implantedinto the spine of a patient. The separation between the externalsurfaces of the body portions (marked as 26 in FIG. 4 or as 103 in theFIG. 13) defines the intervertebral separation of adjacent vertebra or aimplant height.

In some embodiments, the body portions 1, 2 can be configured togenerally define a wedge structure. For example, the body portions 1, 2can each define an internal contact surfaces 19, 29 (see FIG. 4). Thecontact surfaces 19, 29 of the respective body portions 1, 2 can each bedefined at least partially by top surfaces of structural components ofthe body portions 1, 2. In some embodiments, the contact surfaces 19, 29can be oriented at an incline relative to a longitudinal axis of theimplant 25.

As shown in FIG. 4, the structural components of the body portions 1, 2can each comprise one or more structures or walls that rise or extendfrom the outer surface or face of the body portions 1, 2. Further, thebody portions 1, 2 can each define one or more slots or gaps. Theembodiment illustrated in FIG. 4 illustrates the body portions 1, 2 eachhaving a plurality of raised structures or walls 11, 22, 13, 15, 22, 24.The walls 11, 22, 13, 15, 22, 24 can comprise an angled or decliningportion extending from an upstanding portion toward a base of therespective body portion. In this regard, the walls 11, 22, 13, 15, 22,24 can each define a top surface that at least partially defines therespective contact surfaces 19, 29 of the body portion 1, 2.

For example, the first body portion 1 can comprise three walls 11, 13,15 and a pair of slots or gaps disposed intermediate the walls 11, 13.15. Further, the second body portion 2 can comprise a pair of walls 22,24 in one or more slots or gaps disposed adjacent to the walls 22, 24.Accordingly, the first and second body portions 1, 2 can be interlinkedby interpositioning the walls 11, 13, 15 of the first body portion 1into the slots or gaps of the second body portion 2. As will beappreciated, such interlinking also causes the walls 22, 24 of thesecond body portion 2 to be disposed in the slots or gaps of the firstbody portion 1. In this regard, body portions 1, 2 can at leastpartially enter or overlay each other. Thus, the body portions 1, 2 canbe configured to maximize the expansion ratio of the implant. In otherwords, the ratio of the height of the implant in the expanded state tothe height of the implant in a collapsed state can be maximized.

Additionally, the walls 11, 22, 13, 15, 22, 24 can facilitate alignmentof the first and second body portions 1, 2. Thus, the interlinking thefirst and second body portions 1, 2 can act as a guide for the relativemotion between body portions 1, 2.

As noted above, embodiments the implant 25 can be configured to comprisebody portions having one or more walls and/or one or more slots or gaps.Although it is contemplated that the walls of a body portion may begenerally planar, is also contemplated that one or more of the walls candefine a surface structure that facilitates alignment of the bodyportions relative to each other. Further, it is contemplated that theimplant can incorporate an expansion limiting system. For example, theexpansion limiting system can be formed such that one or more of thewalls defines a surface structure that is operative to control and/orlimit expansion of the body portions relative to each other.

The implant 25 can also comprise an expansion component. The expansioncomponent can be used to cause separation between the first and secondbody portions 1, 2. As shown in FIGS. 2 and 5-6, in one embodiment, theexpansion component can comprise a head portion 4 and a ram member 5.The head portion 4 of the expansion component can act against the firstand second body portions I, 2 to control the expansion or contraction ofthe implant. The ram member 5 can drive the head portion 4 against thefirst and second body portions 1, 2.

In the illustrated embodiment, the head portion 4 and the ram member 5of the expansion component are formed separately from each other.However, in other embodiments, as illustrated in FIG. 29, the headportion and the ram member of the expansion component can be attached toeach other or formed as an integral or monolithic piece.

Referring to FIGS. 2 and 6, the head portion 4 of the expansioncomponent can be formed as a spheroid. However, as discussed furtherabove, the head portion 4 can be configured in any of a variety ofgeometric configurations to facilitate interaction between the expansioncomponent and the first and second body portions 1, 2.

FIG. 6 illustrates the implant in a collapsed state. The head portion 4is positioned adjacent the contact surfaces 19, 29 formed by the firstand second body portions 1,2, and is in contact with the top surfaces ofthe walls 11, 22, 13, 15, 22, 24. The thrust of the head portion 4against the contact surfaces 19, 29 can cause the first and second bodyportions 1, 2 to be separated and moved towards the expanded state shownin FIGS. 5 and 6. Accordingly, the head portion 4 can be fabricated froma non-resilient or rigid material that facilitates expansion of theimplant 25 to a given intervertebral height. However, the head portion 4can alternatively be fabricated from a resilient or elastic material. Insuch embodiments, a resilient head portion 4 can allow the implant 25 tobe compressible. The implant 25 could then be able to provide dynamicspacing and support between adjacent vertebrae. The type of materialused for the head portion 4 can therefore be chosen depending on whetherthe implant 25 is intended to provide support at a given height or at arange of heights (through compressibility of the implant 25). Moreover,the shape and size of the head portion 4, as well as its materialproperties, can be dictated by the type of therapy desired.

In some embodiments, the implant 25 can provide dynamic stabilization ofadjacent vertebrae. For example, the head portion 4 can act as a shockabsorber. Such shock absorption can allow the first and second bodyportions 1, 2 to be moved relative to each other such that the implant25 has a degree of compressibility in an expanded state. Accordingly,the implant 25 can provide dynamic stability between the adjacentvertebrae. For example, the head portion 4 can be formed from a materialwith elastic properties, such as nylon or Teflon. In addition, thematerial should be selected so as to ensure a minimum dimensionalaccuracy, resilience, and stability when the implant experiences loadingin the expanded state.

In embodiments of the implant 25 that provide dynamic stabilization ofadjacent vertebrae, the first and second body portions 1, 2 cantranslate and/or rotate relative to each other. For example, asdiscussed herein, embodiments are provided in which the first and secondbody portions 1, 2 can be aligned relative to each other using alignmentsupports. These supports can generally allow vertical translation of thefirst and second body portions 1, 2. However, it is also contemplatedthat the first and second body portions 1, 2 can rotate relative to eachother to provide a rocking motion between the first and second bodyportions 1, 2 of the implant 25. In such embodiments, the implant 25 maynot use alignment supports to prevent rotational movement and maintainvertical alignment. Instead, the first and second body portions 1, 2 ofthe implant 25 can be can comprise one or more pins or bars, such as endcaps 204, 205 shown in FIGS. 26-28. Such pins or bars can facilitaterelative rotation between the first and second body portions 1, 2 of theimplant 25 such that a resilient head portion 4 allows the upper surfaceof the first body portion 1 and the lower surface of the second bodyportion 2 to be angularly oriented relative to each other. In suchembodiments, the first and second body portions 1, 2 of the implant 25can advantageously expand in a vertical direction and/or rotate about acenter point defined by the head portion 4. This flexibility may providevarious advantages such as dynamic stabilization, customized support,and a precise implant fit that can be tailored to a given intervertebralmorphology.

In addition, the intervertebral implant 25 can comprise a confinementcasing 3. As illustrated in FIG. 2, the body portions 1, 2 and theexpansion component can be at least partially disposed within the casing3. In accordance with the illustrated embodiment, the casing 3 cancomprise first and second ends. A channel 31 can be disposed at thefirst end of the casing 3. The channel 31 can be configured to at leastpartially receive the expansion component therein. In some embodiments,the channel 31 can comprise one or more retention structures (e.g.,threads or ratchet-like mechanism). In such embodiments, the ram member5 of the expansion component can comprise one or more retentionstructures (e.g., threads or ratchet-like mechanism) corresponding tothe retention structures of the channel 31.

Further, the casing 3 can be configured to include a pair of sidewalls33, 34. The sidewalls 33, 34 can extend from a channel portion of thecasing 3 toward the second end of the casing 3. Finally, a lid component32 can be formed at the second end of the casing 3. In this regard, thesidewalls 33, 34, the lid component 32, and an end face of the channel31 can define a compartment of the casing 3.

In accordance with an embodiment, the compartment of the casing 3 can beconfigured such that the first and second body portions 1, 2 can bedisposed therein. In this regard, the compartment and the channel 31 canbe configured to at least partially house the expansion component andthe first and second body portions 1, 2. Accordingly, one of theadvantages of such an embodiment is that the casing 3 can restrict orlimit one or more degrees of freedom of movement of the expansioncomponent and the first and second body portions 1, 2.

For example, the casing 3 can be configured to restrict or limitrelative motion of the body portions 1, 2 in a horizontal direction.Accordingly, the first and second body portions 1, 2 can be generallyguided in vertical displacement during expansion or contraction of theimplant. Further, the casing 3 can be configured to restrict or limitmovement of the expansion component—especially if the head portion 4 isformed separately from the ram member 5. In this regard, the headportion 4 (shown as a spheroid in FIGS. 2 and 5-6) can be restrictedfrom movement other than along a longitudinal axis of the implant. Thus,movement of the first and second body portions 1, 2 and the expansioncomponent can be controlled or limited to selected directions such thatmovement of the expansion component efficiently and effectively causesexpansion or contraction of the implant 25. Further, these componentscan be safely held together in the casing 3 in anticipation ofinstallation and implantation, thus facilitating both handling andinstallation.

Moreover, in the embodiments shown in FIGS. 1-6 and the embodimentsshown in FIGS. 7-20, the casing 3 can comprise a cylindrical shape withthe compartment disposed intermediate the sidewalls 33, 34 to allow themovement of body portions. Additionally, the lid component 32 of thecasing 3 can provide distal confinement to the body portions 1, 2. Thechannel 31 can be configured to allow introduction of deployment toolsof the implant 25, such as a deployment end 7 of an expansion tool 10shown in FIGS. 2 and 5-6.

In use, the ram member 5 is actuated by the expansion tool 10. In someembodiments, the expansion tool 10 can engage a proximal end orengagement structure of the ram member 5 in order to impart rotation tothe ram member 5. As shown in FIGS. 5-6, the head portion 4 contacts theinclined contact surfaces of the first and second body portions 1, 2. Inembodiments wherein the head portion 4 is formed separately from the rammember 5, the head portion 4 is pushed by an end of the ram member 5.Once installed in the casing 3, the ram member 5 and the head portion 4can be at least partially disposed in the interior of the implant.

As noted above, the ram member 5 can comprise more retention structures.In some embodiments, the retention structures can comprise one or morethreads. Further, the channel 31 can comprise corresponding threadsconfigured to mate with the threads of the ram member 5, as shown inFIG. 5. Thus, the ram member 5 can be a threaded part (such as athreaded rod) having a first end configured to transmit axial forceagainst the head portion 4 and a second end configured to mate with aportion of the expansion tool. The second end of the ram member 5 cancomprise an engagement element configured to receive an end of the tool7. The engagement element can comprise a geometric shape correspondingto any of a variety of geometric tooling shapes known in the art, suchas an Allen hex or other types of unions. In other embodiments, theretention structures can comprise a ratchet-like mechanism between theram member 5 and the channel 31.

One of the unique advantages provided by a threaded rain member 5 and athreaded channel 31 is that the implant can be precisely expandable withan almost endless selection of the heights. Further, the ram member 5can also be reversible, thereby reducing the implant height, which canallows the implant to be safely removed or adjusted. In addition,threads can prevent collapse or closure of the implant.

In some embodiments, for ease of reversibility, the implant can furthercomprise one or more elastic recovery elements 8. The elastic recoveryelement 8 can extend between and interconnect the body portions 1, 2.The elastic recovery element 8 can limit and/or restrict one or moredegrees of movement of the components of the implant. For example, theelastic recovery element 8 can limit the total or maximum expansion ofthe implant or limit axially transverse movement of the expansioncomponent.

The elastic recovery elements 8 could be, for example, a mesh withelastic properties (e.g. a mesh with elastic material, a cut mesh, etc.)or even one or more elastic bands surrounding the body portions 1, 2. Inembodiments using an elastic band, the body portions 1, 2 can furthercomprise an elastic groove by which the elastic band can be seated onbody portions 1, 2 to prevent displacement of the elastic band from adesired position. In embodiments using a mesh, the match could beanchored to the casing 3 or the body portions 1, 2 using affixingelements, such as projections extending from the casing 3 or the bodyportions 1, 2, if considered necessary. Further, as discussed above, theelastic recovery elements 8 can be interconnected with areas of the bodyportions 1, 2 such that the elastic recovery element 8.

As it has been shown schematically in the embodiments shown in thefigures, because of its structure, the implant 25 can be manipulatedthrough a minimally invasive access device space using tools 7, 8, 9,10. For example, the tool 10 may be manual or powered. However, it iscontemplated that an Allen-type tool can be sufficient if the surgeonexercises adequate command for controlled turning of the tool.Optionally, the tool can also comprise tubular supports 8, 9 with abayonet connection or anchor, according to known techniques.

FIGS. 7-20 illustrate other embodiment of the implant and its componentsshown in FIGS. 1-6. The embodiments shown in FIGS. 7-20 providestructural variations to the above-described body portions. In order toavoid repetition, components of the embodiments of the implant shown inFIGS. 7-20 that are similar to corresponding components shown anddescribed in FIGS. 1-6 are labeled with identical numerals, andtherefore will not be discussed in depth.

The body portions 1, 2 of FIGS. 7-20 can define the same generalexterior shape as those of FIGS. 1-6; in other words, the body portions1, 2 can have the general form of a wedge and can be formed having oneor more raised structures or walls and one or more slots or gapsdisposed adjacent to the walls.

In accordance with the embodiment illustrated in FIGS. 12-13, 15 and15-20, the first and second body portions 1, 2 of the implant cancomprise one or more respective structures or walls 101, 102, 201, 202,203 that rise or extend from the outer surface or face of the bodyportions 1, 2. Additionally, the side walls 101, 102, 201, 202, 203 canbe configured to comprise corresponding protrusions 106, 107, 108, 109,110 and slots 206, 207, 208, 209, 210. The protrusions 106, 107, 108,109, 110 and slots 206, 207, 208, 209, 210 can be configured tofacilitate alignment of the first and second body portions 1, 2. Thiscan improve the vertical guidance between the body portions 1, 2, thuspreventing rotational movement or axial translation between the bodyportions 1, 2.

Further, in accordance with some embodiments, the implant can comprisean expansion limiting system. The expansion limiting system can restrictthe maximum separation or expansion between body portions 1, 2. Such afeature can be useful in some embodiments if the elastic recoveryelement 8 is not used.

For example, as shown in FIGS. 12-13 and 15-20, the expansion limitingsystem can comprise one or more tabs 104, 105 extending from the firstbody portion 1 that are configured to contact with end caps 204, 205located on the second body portion 2. In the illustrated embodiment,there are two tabs 104, 105 projecting from an end of the first bodyportion 1 and the end caps 204, 205 have been formed using a bolt thatextends through the walls 201, 202, 203. In some embodiments, the endcaps 204, 205 can also serve as limits to a degree of relative rotationbetween the first and second body portions 1, 2. Of course, otherexpansion limiting systems can be formed by one of skill in the art.

Furthermore, in some embodiments, the expansion limiting system of theimplant 25 can be configured to provide a retention force between thefirst and second body portions 1, 2 such that the first and second bodyportions 1, 2 are urged toward a collapsed state. In an embodiment,external or internal structures of the body portions 1, 2, such as thetabs 104, 105, can be used to implement such an elastic system ofrecovery. Further, the implant 25 can comprise additional components,such as a coil or a leaf spring that can be elastically deformed whenthe first and second body portions 1, 2 are moved to an expanded state,thus urging the first and second body portions 1, 2 toward the collapsedstate. In this regard, the coil or leaf spring can exert a force tendingto collapse the body portions 1, 2. However, it is contemplated thatmodified structures or features can be implemented to provide aretention force between the first and second body portions 1, 2.

FIGS. 21-32 show yet another embodiment of an intervertebral implant. Assimilarly noted above with respect to FIGS. 7-20, in order to avoidrepetition, components of the embodiments of the implant shown in FIGS.21-32 that are similar to corresponding components shown and describedin FIGS. 1-20 are labeled with identical numerals, and therefore willnot be discussed in depth.

In accordance with the embodiments shown in FIGS. 21-32, the expansioncomponent can comprise a head portion 4 and a ram member 5 that areinterconnected. For example, the head portion 4 can be coupled to theram member 5 via an elastic element, such as a spring. Thus, theexpansion component would advantageously be handled as a single piecewhen one unscrews the ram member 5. In other words, some embodimentsprovide that the head portion 4 can be retained or coupled to the rammember 5. Accordingly, such embodiments could be implemented without theneed to place, for example, an elastic recovery element as discussedabove in other embodiments.

Further, in some embodiments, the head portion 4 can comprise a cavityor hollow portion 290. In this regard, in order to improve the elasticproperties of the head portion 4, the cavity or hollow portion 290 canbe drilled in the sphere. In this way, the head portion 4 can absorbimpact made in the intervertebral space through compression into thecavity or hollow portion 290. Moreover, as noted herein, the headportion 4 can be fabricated from a resilient, compressible material.

Referring now to FIGS. 23, 25, 26, and 31, some embodiments can beconfigured such that a surface or outer face of body portions 1, 2comprises projections 199. The projections 199 can extend from thesurface of the body portions 1, 2 for promoting osseointegration of theimplant with the vertebrae. To encourage this integration, the implantcan also comprise porous materials suitable for the purpose ofosseointegration.

With regard to FIGS. 22, 25-28, and 30-32, some embodiments can beconfigured such that the body portions 1, 2 comprise alignment supports304, 305, 402, 403, 404, 405. The alignment supports 304, 305, 402, 403,404, 405 can extend from the body portions 1, 2 and be configured toprevent rotation, and/or torsion between the body portions 1, 2 duringrelative vertical movement between the body portions 1, 2. FIGS. 27 and28 illustrate orientations of the body portions 1, 2 in which the bodyportions 1, 2 are rotated relative to each other. In some embodiments,such rotation may not be prevented by the implementation of an expansionlimiting system alone. In the illustrated embodiment, the expansionlimiting system can comprise the interaction of the slots 221, 241 withthe end caps 204, 205. As shown, the end caps 204, 205 have been formedusing a bolt. However, in some embodiments, the expansion limitingsystem can be used in conjunction with the alignment supports 304, 305,402, 403, 404, 405 to prevent rotation of the body portions 1, 2relative to each other during relative vertical movement thereof.Furthermore, in embodiments that do not include the alignment supports304, 305, 402, 403, 404, 405 or corresponding protrusions 106, 107, 108,109, 110 and slots 206, 207. 208, 209, 210 discussed above, the end caps204, 205 can facilitate a degree of relative rotation between the firstand second body portions 1, 2.

Similarly, the body portions 1, 2 can comprise a rounded edge 401, asshown in FIG. 30. Thus, in such an embodiment, the head portion 4 of theexpansion component can be seated against the rounded edge 401 duringlongitudinal movement of the expansion member. Such an embodimentadvantageously provides a greater area of contact with the body portions1, 2, and distributes a load more evenly through the components of theimplant.

In accordance with another embodiment, FIG. 33 illustrates a perspectiveview an installation tool 500 and an intervertebral implant 502 seatedin an engagement portion 510 of the tool 500. As illustrated, theinstallation tool 500 can comprise a handle portion 512 and a deploymentportion 514. The installation tool 500 can be used to place and deploythe implant 502 during a medical procedure. As discussed herein,embodiments of the installation tool 500 and the implant 502 providesignificant advantages over prior art installation tools and implants.

FIGS. 34-37 illustrate the installation tool 500 in greater detail. Inthe illustrated embodiment, the handle portion 512 can be configured tofacilitate placement and operation of the implant 502, such ascontrolling the expansion or contraction of the implant. As shown inFIG. 34, the engagement portion 510 of the installation tool 500 cancomprise one or more protrusions 520 extending distally from a distalend 522 of the deployment portion 514. In other words, the engagementportion 510 can extend distally from the distal and 522 of thedeployment portion 514. The one or more protrusions 520 of theengagement portion 510, as well as other structures of the installationto 500, can be used to engage and retain the implant 502 on theinstallation tool 500 during placement of the implant 502. Further, insome embodiments, the one or more protrusions 520 and other structurescan also enable a surgeon to deploy, remove, expand, and/or contract theimplant 502.

Referring now to FIG. 34, in some embodiments, the protrusions 520 ofthe engagement portion 510 can be configured to extend generallyparallel relative to a longitudinal axis of the deployment portion 514.Further, the protrusions 520 can comprise surfaces 524 that face eachother. In some embodiments, the surfaces 524 can be flat. Additionally,the surfaces 524 can face each other and be generally parallel relativeto each other. In accordance with at least one embodiment, the surfaces524 can serve to engage a portion of the implant 502 during placementand operation of the implant 502. For example, the surfaces 524 canmaintain a rotational orientation of the implant 502 relative to thelongitudinal axis of the deployment portion 514.

In other words, in some embodiments, the engagement portion 510 can beconfigured to restrain at least one degree of movement of the implant502 relative to the installation tool 500. However, as will beappreciated, the engagement portion 510 can be configured with a singleprotrusion having a uniquely shaped engagement structure that can matewith a corresponding engagement structure of the implant 502. Forexample, the protrusion can have any of a variety of shapes, such as astar or flat shape, a square shape, or other polygonal shapes. In thisregard, the implant 502 can also comprise a structure corresponding tothe shape of the protrusion; the structure can be a recess or otherprotrusion that facilitates mating engagement between the implant 502and the protrusion of the engagement portion 510.

Referring still to FIG. 34, the handle portion 512 of the tool 500 cancomprise several components. For example, in the illustrated embodiment,the handle portion 512 comprises a handle member 530, a first rotatingmember 532, and a second rotating member 534. As shown at FIGS. 34-36,the handle member 530, the first rotating member 532, and the secondrotating member 534 get each comprise a distal elongate component thatcan form a part of the deployment portion 514 and a proximal componentthat can form a part of the handle portion 512.

For example, as illustrated in FIG. 34, the handle member 530 includes agripping component 540 and an elongate tubular component 542. Thegripping component 540 is coupled to the tubular component 542 such thatthe tubular component 542 does not rotate with respect to the grippingcomponent 540. However, as will be discussed further here in, someembodiments of the tool 500 provide that at least one of the first andsecond rotating members 532, 534 rotate with respect to a longitudinalaxis of the handle member 530. Accordingly, a surgeon can grasp thegripping component 540 in one hand and use the other hand to rotate oneof the first and second rotating members 532, 534. In this manner, thesurgeon can control implant 502.

As discussed above, the deployment portion 514 can comprise theengagement portion 510. In some embodiments, the handle member 530 cancomprise the engagement portion 510. More specifically, the tubularcomponent 542 can comprise the engagement portion 510. As such, in someembodiments the surgeon can grasp and use the gripping portion 540 twoper event rotation of the engagement portion 510. Thus, the surgeon canensure that the implant 502 maintains a desired rotational alignmentduring placement and deployment at the deployment site.

Referring now to FIG. 35, the first and second rotating members 532, 534are shown separate from the handle member 530. The first rotating member532 can comprise a first knob in 550 at an actuation component 552. Insome embodiments, the first knob 550 is coupled to the actuationcomponent 552 to prevent relative movement between the first knob 550 atthe actuation component 552. Further, the actuation component 552 can beconfigured to pass through a part of the tubular component 542 of thehandle member 530. For example, the actuation component 552 can extendthrough a bore of the tubular component 542. The actuation component 552can be rotatable with respect to a bore or opening of the tubularcomponent 542. Further, the actuation component 552 can comprise agenerally cylindrical outer profile.

Additionally, in the illustrated embodiment actuation component 552 isconfigured as an elongate tubular member having a rotational connector554 disposed at a distal end 556 thereof. In this regard, the rotationalconnector 554 can be configured to interact with the implant 502 so asto control one or more operations of the implant 502. For example, whenthe implant 502 is engaged with the installation tool 500, therotational connector 554 can engage the ram member of the implant 502 tomove the implant 502 to an expanded or contracted configuration.

In some embodiments, the rotational connector 554 can comprise one ormore protrusion that engage the ram member of the implant 502. Forexample, in the illustrated embodiment, the rotational connector 554 cancomprise one or more protrusion that extend distally from the actuationcomponent 552. In particular, the rotational connector 554 can comprisea pair of generally rectangular protrusions that extend transverselyrelative to a longitudinal axis of the first rotating member 532.

Additionally, FIG. 36 illustrates an embodiment of the second rotatingmember 534. The second rotating member 534 can comprise a second knob560 and a retention component 562. Further, the retention component 562can comprise a fastening portion 564 disposed at a distal and 566thereof. The second knob 560 can be coupled to the retention component562 to prevent relative rotational therebetween. Accordingly, in anembodiment, rotation of the second knob 560 can cause rotation of thefastening portion 564. In some embodiments, the fastening portion 564can comprise one or more threads that are configured to engage orcorresponding threads of the implant 502. Further, the retentioncomponent 562 can be configured to extend within a bore or opening ofthe actuation component 552 of the first rotating member 532. Theretention component 562 can be rotatable with respect to the bore oropening of the actuation component 552. Further, the retention component562 can comprise a generally cylindrical outer profile.

In this regard, the second rotating member 534 can be configured suchthat the fastening portion 564 extends distally beyond at least aportion of the distal end 556 of the actuation component 552. Further,both the fastening portion 564 of the second rotating member 534 and therotational connector 554 of the first rotating member 532 can beconfigured to extend distally beyond at least a portion of the distalend 522 of the tubular component 542.

For example, as illustrated in FIG. 37, the retention component 562 canextend within the actuation component 552, which can likewise extendwithin the tubular component 542. The retention component 562 can rotaterelative to both the actuation component 552 and the tubular component542 in order to engage a recess 570 of the implant 502. In someembodiments, the recess 570 can be threaded. Thus, in use, a casing 504of the implant 502 can be positioned with in the engagement portion 510of the tool 500 and the second knob 562 can be rotated to cause theretention component 562 to engage the recess 570 of the implant 502 inorder to couple the implant 502 with the tool 500. In other embodiments,the implant 502 can comprise a recess that is not threaded, but thatcomprises one or more protrusions or detents that allow the retentioncomponent 562 to engage the implant 502.

The coupling between the implant 502 and the tool 500 is facilitated atleast in part due to the engagement between the one or more protrusions520 of the engagement portion 510 that serve to restrict the relativerotation between the casing 504 of the implant 502 and the tool 500.Further, the engagement between the retention component 562 and theimplant 502 can serve to draw the casing 504 of the implant 502 into theengagement portion 510 of the tool 500. In this manner, the secondrotating member 534 can facilitate retention between the tool 500 andthe implant 502. Embodiments of this system provide various benefits andadvantages such as improved engagement between the implant 502 and thetool 500, as well as precise implant actuation and improved deploymentcontrol for the surgeon.

Once the implant 502 is engaged by the retention component 562, theactuation component 552 can also be used to engage a portion of theimplant 502. For example, the actuation component 552 can be configuredto engage a ram member 572 of the implant 502. The first knob 550 can berotated to cause the actuation component 552 to rotate the ram member572 of the implant 502. As the ram member 572 rotates, a head 574 of theram member 572 can be urged against at least one inclined surface 576 ofthe implant 502, which causes first and second portions 578, 580 of theimplant 502 to move relative to each other to create a change in implantheight, such as by moving from an expanded to a contractedconfiguration, or vice versa. In this manner, the first rotating member532 can facilitate expansion or contraction of the implant 502.

Additionally, it is contemplated that in some embodiments, the retentioncomponent 562 and the actuation component 552 can be axially movablerelative to the tubular component 542. In this manner, as the ram member572 is rotated, which causes the ram member 572 to be drawn into thecasing 504 of the implant 502, the retention component 562 and theactuation component 552 can move axially with the proximal end of theram member 572 to maintain engagement therebetween. In such anembodiment, it is also contemplated that the proximal end of the casing504 can abut one or more shoulders or stops formed in the engagementportion 510 of the tool 500 during expansion of the implant 502. Assuch, axial movement of the retention component 562 and the actuationcomponent 552 can take place while the proximal end of the implant 502abuts the shoulders or stops of the engagement portion 510. Such anembodiment can ensure that the casing 504 is fully engaged with theengagement portion 510 during placement and deployment. However, inother embodiments, it is contemplated that the engagement portion 510 ofthe tool 500 can be configured to allow the proximal end of the casing504 to be drawn further thereinto without creating interference againstthe proximal end of the casing 504 during expansion of the implant.

One of the unique advantages of the illustrated embodiment of the tool500 is that in use, both the tubular component 542 and the actuationcomponent 552 can operate to restrict rotational movement of the casing504 of the implant 502 while the retention component 562 is rotated toeither engage or disengage with the rain member 572 of the implant 502.Thus, even after placement of the implant 502, the torque required todisengage the retention component 562 from the recess 570 of the rammember 572 can be generally negated by applying a countervailing torqueto the tubular component 542 and the actuation component 552. Thus, oncein a deployed state or final position, the placement of the implant 502need not be disturbed during disengagement of the tool 500. Similaradvantages are present with regard to relative rotation between theactuation component 552 and the tubular component 542 in order to movethe implant 502 to an expanded or a contracted configuration.Accordingly, the tool 500 provides the surgeon with a superior degree ofcontrol in placing and deploying the implant 502.

With regard now to FIG. 38, another embodiment of an intervertebralimplant 600 illustrated. In FIG. 38, the implant 600 shown in acollapsed or undeployed configuration. As such, the implant 600 shown inFIG. 38 defines a minimal passing profile that allows the implant 600 tobe placed at a desired intervertebral position for deployment. Asdiscussed herein, the implant 600 can be maneuvered and operated usingan installation tool, such as the tool 500 discussed above. The implant600 can comprise a distal and 602 and a proximal end 604. The proximaland 604 can be engaged by the installation tool in order to place andcause the expansion or contraction of the implant 600.

As shown in FIG. 39, the illustrated embodiment of the implant 600 cancomprise several components. The implant 600 can comprise an expansioncomponent 610, a casing 612, a first body portion 614, and a second bodyportion 616. The expansion component 610 can have a ram member and ahead. In at least one embodiment, the operation of the implant 600 issimilar to the operation of the implants discussed above.

For example, in the embodiment illustrated in FIGS. 38-48, the casing612 of the implant 600 is configured to receive the expansion component610. Further, a threaded portion or ram member 620 of the expansioncomponent 610 can threadably engage internal threads of an inner bore630 of the casing 612. In this regard, the expansion component 610 canrotate relative to the casing 612 by application of a rotational forceto the expansion component 610. In order to facilitate transfer of arotational force to the expansion component 610, the expansion component610 can comprise one or more engagement structures 632 disposed at aproximal end 634 of the expansion component 610. Accordingly, asillustrated in the exemplary embodiment of FIG. 37, a portion of aninstallation tool can engage one or more engagement structures 632 ofthe expansion component 610 in order to transfer a rotational force tothe expansion component 610 via the ram member 620.

Further, the rotational movement of the expansion component 610 cancause the expansion component 610 to move axially relative to the casing612. As a result, a head 636 of the expansion component 610 disposed ata distal end the 638 of the expansion component 610 can be urged againstinternal structures are surfaced as of the first and second body portion614, 616. In this regard, the first and second body portion 614, 616 canbe separated by the rotational movement of the expansion component 610,thus causing the implant 600 to expand.

Furthermore, in some embodiments, the rotational movement of theexpansion component 610 can be isolated from the casing 612 byrestricting rotational movement of the casing 612. In this regard, thecasing 612 can comprise one or more structures that can be engaged bythe tool 500 in order to retain the casing 612 in a given rotationalposition as the expansion component 610 is rotated. In other words, asdiscussed herein, the tool 500 can be configured to engage multipleportions of the implant 600 in order to selectively rotate portions ofthe implant 600 relative to each other or portions of the implant 600relative to portions of the tool 500.

In the illustrated embodiment of FIG. 39, the easing 612 can compriseone or more engagement surfaces 640. As shown, the casing 612 cancomprise a pair of engagement surfaces 640 that are disposed on oppositesides of the casing 612. The illustrated embodiment indicates that thecasing 612 can be configured to define a generally cylindricalconfiguration and that the engagement surfaces 640 can be formed asgenerally flat sections disposed along the perimeter of the casing 612.In this embodiment, the engagement surfaces 640 can be configured tomate with the surfaces 524 of the protrusions 520 of the engagementportion 510 of the tool 500.

In use, when the surfaces 524 of the engagement portion 510 are matedwith the engagement surfaces 640 of the casing 612, relative rotationalmovement is restricted between the elongate tubular component 542 of thetool 500 and the casing 612 of the implant 600. Thus, other portions ofthe tool 500 can actuate other portions of the implant 600. For example,the actuation component 552 can rotate the expansion component 610 whilethe rotational movement of the casing 612 is fixed. Accordingly, theimplant 600 can be actuated by the tool 500 to control the height and/orexpansion of the implant 600.

As discussed above, the first and second rotating members 532, 534 ofthe installation tool 500 can be used to interact with the implant 600.One of the unique advantages provided by the embodiments of the implant600 at the tool 500 is that relative motion between the tool 500 at theimplant 600 can be controlled using the tool 500. For example, as notedabove, the tubular component 542 of the handle member 530 can engagewith the casing 612 of the implant 600, thereby preventing rotation ofthe implant 600 relative to the handle member 530.

Additionally, the fastening portion 564 of the second rotating member534 can engage the recess 570 of the expansion component 610 of theimplant 600 in order to couple the implant 600 to the tool 500. Further,in some embodiments, the tool 500 can be configured to prevent rotationof the expansion component 610 as the fastening portion 564 of thesecond rotating member 534 is coupled to the recess 570 of the implant600. In other embodiments, the implant 600 can comprise a recess that isnot threaded, but that comprises one or more protrusions or detents thatallow the fastening portion 564 to engage the implant 600. Thus, thefastening portion 564 can be axially urged distally into the recess ofthe implant 600 to become engaged therewith. In order to disengage thefastening portion 564 from the implant 600 in such an embodiment, theactuation component 552 can abut the proximal end of the implant 600 toprevent proximal movement of the implant 600 as the fastening portion564 is proximally removed from the recess of the implant. In suchembodiments, the tool 500 can be coupled to or disengaged from theimplant 600 without causing torque or axial movement to be passed to theimplant 600 once in a desired deployment position.

For example, the rotational connector 554 of the first rotating member532 can engage the expansion component 610 of the implant 600 in orderto prevent rotation of the expansion component 610 relative to the firstrotating member 532. Thus, in order to couple the fastening portion 564to the recess 570, the surgeon can position the implant 600 against theengagement portion 510, engage the rotational connector 554 with theexpansion component 610, grasp the first knob 550, and rotate the secondknob 560 relative to the first knob 550 in a given direction. Similarly,to detach the fastening portion 564 from the recess 570, the surgeon canrotate the second knob 560 relative to the first knob 550 in a directionopposite to the given direction.

Finally, the interaction of the tool 500 in the implant 600 is alsounique in that the first rotating member 532 can be used to actuateexpansion or contraction of the implant 600 through rotation while thetubular component 540 to engage as the casing 612 to prevent the implant600 from rotating with the rotation of the first rotating member 532. Inother words, rotation of the casing 612 can be prevented during rotationof the expansion component 610. In use, the surgeon may rotate the firstand second rotating members 532, 534 relative to the handle member 530in order to rotate the expansion component 610 relative to the casing612. Thus, the expansion component 610 can cause the first and secondbody portions 614, 616 of the implant 600 to move relative to eachother. In this manner, the tool 500 enables the surgeon to carefullycontrol expansion and contraction of the implant 600. The surgeon canisolate rotational movement of portions of the tool 500 relative to eachother, portions of the implant 600 relative to each other, and portionsof the tool 500 relative to portions of the implant 600.

FIG. 40 illustrates a cross-sectional side view of the implant 600 in acollapsed configuration or state. As illustrated, the installation tool500 can be coupled to the implant 600 in order to position and to deploythe implant 600. In this regard, as previously noted with respect toFIG. 37, the retention component 562 can be engaged with the recess 570of the implant 600. Although FIGS. 40 and 41 indicate that the recess570 is threaded, the recess 570 can comprise threads, protrusions, ordetents that facilitate engagement between the retention component 562and the recess 570. Further, the rotational connector 554 of theactuation component 552 can be engaged with the engagement structures632 of the expansion component 610 in order to rotate the expansioncomponent 610.

As shown FIG. 40, the first and second body portions 614, 616 cancomprise respective contact surfaces 680, 682. The contact surfaces 680,682 can be generally transversely oriented with respect to alongitudinal axis of the implant 600. In some embodiments, the contactsurfaces 680, 682 can be inclined with respect to the longitudinal axis.For example, as shown in FIG. 40, the contact surfaces 680, 682 can begenerally planar surfaces configured to contact the head 636 of theexpansion component 610. As discussed similarly above with respect toother embodiments of the implant, as the head 636 is urged distally ortoward a distal end 684 of the casing 612, the contact against the head636 and the contact surfaces 680, 682 can generally cause the first andsecond body portions 614, 616 to move apart from each other, asillustrated in FIG. 41.

FIG. 41 illustrates the implant 600 in an expanded state. As shown, theexpansion component 610 has been located in order to cause translationof the head 636 thereof in a distal direction. Accordingly, the firstand second body portions 614, 616 have been separated to cause theimplant 600 to expand. As will be appreciated by one skilled in the art,the degree of expansion of the implant 600 depends on the rotation ofthe expansion component 610. As such, a surgeon can specificallyconfigure the implant 600 to have a desired intervertebral height.

In some embodiments, as mentioned herein, the implant 600 can be used tofacilitate vertebral fusion or to provide dynamic support betweenvertebral bodies. For example, after placing and deploying the implant600 to a desired intervertebral height between adjacent vertebralbodies, BMP or graft material can be inserted into the implant 600 inorder to promote fusion between the vertebral bodies. Alternatively, theimplant 600 can be configured to provide a degree of resilience and/orcompressibility in the expanded state in order to allow the implant toprovide dynamic support between vertebral bodies. In some embodiments,the head portion 626 of the expansion component 610 can comprise aresilient, compressible material. In other embodiments, other componentsof the implant 600 can be deflectable, compressible, and/or resilient inorder to allow the implant 600 to provide dynamic spacing. Accordingly,the height or spacing of the implant 600 can be dynamic in that theapplication of compressive forces to the implant 600 can cause theheight of the implant 600 to fluctuate within a given range. The dynamicresponse of the implant in some embodiments can allow the implant toprovide a natural resilient spacing between vertebral bodies.

With reference now to FIG. 42, a top view is shown of the implant 600and the engagement portion 510 of the tool 500. As discussed above, theimplant 600 can comprise the casing 612 and one or more engagementsurfaces 640 dispose on the casing 612. Further, the installation tool500 can comprise the engagement portion 510 that includes a pair ofprotrusions 520 that each comprises a surface 524. As illustrated inFIG. 42, the implant 600 can be received in the engagement portion 510of the installation tool 500 with the engagement surfaces 640 of thecasing 612 being mated against the surfaces 524 of the protrusions 520.The engagement or mating between the engagement surfaces 640 and thesurfaces 524 can serve to prevent rotational movement of the casing 612relative to the engagement portion 510. Therefore, as described above,other components of the tool 500 can be used to rotate other componentsof the implant 600 in order to operate the implant 600.

As similarly mentioned above, although the surface is 524 of theengagement portion 510 of the tool 500 are illustrated as generally flatsurfaces, the surfaces 524 can also comprise one or more non-planarstructures. In such embodiments, the non-planar structures of thesurfaces 524 can engage or mate with one or more correspondingstructures on the engagement surfaces 640 of the casing 612 of theimplant 600. For example, such structures could include elongatedgrooves and ridges that further facilitate axial alignment between theimplant 600 and the tool 500.

FIG. 43 is a rear perspective view of the implant 600 illustratingimminent engagement between the retention component 562 of the secondrotating member 534 and the threaded recess of the expansion component610 of the implant 600. In this figure, other portions of the tool 500are omitted in order to illustrate the interaction between the retentioncomponent 562 and the expansion component 610.

FIGS. 44-45 are perspective views of the expansion component 610. Asillustrated, the expansion component 610 can comprise the head 636disposed at the distal end 638 thereof and the ram member or threadedportion 620 disposed at the proximal end 634 thereof. Additionally, theexpansion component 610 can comprise one or more engagement structures632. The engagement structures 632 can comprise at least the recess 570,such as threads, protrusions, or detents. Further, the engagementstructures 632 can comprise a slot 690 extending generally transverselyrelative to a longitudinal axis of the expansion component 610. As shownand discussed herein, the recess 570 can be used to engage with theretention component 562 of the second rotating member 534 of the tool500. Further, the slot 690 can be used to engage with the rotationalconnector 554 of the first rotating member 532 of the tool 500.Furthermore, the expansion component 610 can comprise a shaft component692 that extends between the head 636 and the ram member or threadedportion 620 of the expansion component 610. In some embodiments, theshaft component 692 can be configured as a substantiallynon-compressible component. However, it is also contemplated that insome embodiments, in which dynamic vertebral spacing is desired, theshaft component 692 can be compressible. For example, the shaftcomponent 692 can provide resilient spring-like spacing between the head636 and the threaded portion 620. Additionally, in some embodiments boththe head 636 and the shaft component 692 can comprise a compressibleand/or resilient material.

Referring now to FIGS. 47-48, the first and second body portions 614,616 can be configured similar to the body portions discussed above. Forexample, the first and second body portions 614, 616 can form awedge-shaped component and can be formed having one or more structuresor walls that rise or extend from the outer surface or face of the bodyportions 614, 616 and one or more slots or gaps disposed adjacent to thewalls.

In accordance with the embodiment illustrated in FIGS. 47-48, the firstand second body portions 614, 616 of the implant can comprise raisedstructures or walls 702, 704, and 706, and 708 and 710, respectively.The walls 702, 704, 706, 708, and 710 can be configured to allow thefirst and second body portions 614, 616 to be at least partially nestedwith each other. For example, the walls 702, 704, 706, 708, and 710 canbe configured with respective widths and spacings that allow the walls702, 704, 706, 708, and 710 to generally overlap with each other, asshown in FIG. 49.

In some embodiments, at least some of the walls 702, 704, 706, 708, and710 can be configured to comprise corresponding at least one protrusionand/or at least one slot. The protrusions and slots can be configured tofacilitate alignment of the first and second body portions 614, 616.This can improve the vertical guidance between the body portions 614,616, thus preventing rotational movement or axial translation betweenthe body portions 614, 616.

In accordance with at least one embodiment, walls that are adjacent toeach other when the first and second body portions 614, 616 areinterlinked or nested can collectively comprise at least one protrusionand at least one slot configured to receive the protrusion. In otherembodiments, walls that are adjacent to each other when the first andsecond body portions 614, 616 are nested can collectively comprise atleast a pair of protrusions and a pair of corresponding slots configuredto receive the protrusions.

The protrusions and the slots can be configured to be linear. Thus, thefirst and second body portions 614, 616 can be translated relative toeach other without rotation between the first and second body portions614, 616. In other embodiments, the protrusions and slots can be arcuatein shape such that the first and second body portions 614, 616 rotaterelative to each other during movement thereof. Furthermore, it iscontemplated that the protrusions and slots could comprise amotion-limiting mechanism, such as a step or tooth that extends from theslot to engage the protrusion for limiting the movement of the first andsecond body portions 614, 616 relative to each other.

In some embodiments, a first of the adjacent walls can comprise one ormore protrusions and/or one or more slots while a second of the adjacentwalls can comprise one or more slots and/or one or more protrusionscorresponding to the protrusions and/or slots of the first of theadjacent walls. Further, in some embodiments, both of the first andsecond adjacent walls can also comprise at least one protrusion and atleast one slot that correspond to each other.

For example, the wall 706 of the first body portion 614 can comprise aprotrusion 720 and a pair of slots 730, 732. Additionally, the wall 702can comprise a protrusion 726 and a pair of slots 734, 736. Further, thewall 708 can comprise a pair of protrusions 740, 742 and a slot 744.Furthermore, the walls 710 can comprise a pair of protrusions 750, 752and a slot 754. In this regard, FIG. 48 illustrates a cross-sectionaltop view of an embodiment of the implant 600 where the walls of thefirst and second body portions 614, 616 comprise protrusions and slotsthat correspond to each other. As similarly noted above, the walls 708and 710 of a second body portion 616 can be interpositioned between thewalls 702, 704, 706 of the first body portion 614. In this regard, therespective protrusions and slots can be aligned with each other, and thefirst and second body portions 614, 616 can be interlinked and move in acollapsing or expanding direction while maintaining rotational andtranslational alignment with each other.

Accordingly, in such an embodiment of the implant 600, the expansioncomponent 610 can actuate movement the first and second body portions614, 616, and alignment of outer surfaces 760, 762 of the respectiveones of the first and second body portions 614, 616 can be generallymaintained during expansion or contraction.

Further, in accordance with some embodiments, the implant 600 cancomprise an expansion limiting system. The expansion limiting system canrestrict the minimum or maximum separation or expansion between thefirst and second body portions 614, 616. For example, as shown in FIGS.40-41 and 47-48, the expansion limiting system can comprise a pluralityof apertures 770 in the first body portion 614 which a pin 772 can bereceived. Additionally, the second body portions 616 can comprise aplurality of slots 774 extending through the walls 708, 710. In use, thepin 772 is inserted through the apertures 770 in the slots 774. As thefirst and second body portions 614, 616 expand or contract relative toeach other, the pin 772 can restrict the relative movement thereof bycontacting the ends of the slots 774, as shown in FIGS. 40-41.

In addition, with regard to FIGS. 46-47, some embodiments can beconfigured such that the first and second body portions 614, 616comprise alignment supports 780, 782, 784, and 786. The alignmentsupports 780, 782, 784, and 786 can extend from the first and secondbody portions 614, 616 and can be configured to prevent rotation, and/ortorsion between the first and second body portions 614, 616 duringrelative vertical movement between the first and second body portions614, 616. Accordingly, it is contemplated that the alignment supports780, 782, 784, and 786 can be used in an embodiment wherein the walls ofthe first and second body portions 614, 616 comprise protrusions andslots to facilitate alignment. In this regard, the alignment supports780, 782, 784, and 786 can further assist in preventing relativerotation between the first and second body portions 614, 616.

As mentioned above, FIG. 48 is a cross-sectional top view of the implant600 illustrating the interaction of the walls of the first and secondbody portions 614, 616. Further, FIG. 48 illustrates the threadedengagement of the expansion component 610 with the casing 612. Asdiscussed above in detail, as the expansion component 610 is rotatedwith respect to the casing 612, the expansion component 610 will move inthe direction of the arrows 790 (depending on whether the rotation isclockwise or counterclockwise). In response to this rotation, the head636 of the expansion component 610 will cause the spacing between thefirst of second body portions 614, 616 to change, resulting in expansionor contraction of the implant 600.

In accordance with some embodiments, the implant can be deployed from adistance of separation of approximately between 6.3 mm to approximately15 mm. The implant can also be configured to expand within any portionof the range. Thus, it is also contemplated that embodiments can beconfigured that are suitable for different patient geometries, whetherwithin or larger than the noted ranges.

Embodiments and components of the implant can be fabricated from metalssuch as titanium or synthetic materials are approved for medical use ofsurgical instruments, such as polyester ester ketone (PEEK) withhydroxyapatite.

The implants disclosed herein can be implanted using a variety ofsurgical methods. These surgical methods comprise additional embodimentsof the present inventions. In accordance with such embodiments, methodsof implanting an expandable intervertebral implant are provided herein.Such methods can include the steps of dilating a pathway to anintervertebral disc, removing the nucleus of the intervertebral disc todefine a disc cavity, scraping vertebral and plates from within the disccavity, and deploying an intervertebral implant in the disc cavity.

In an implementation of the surgical methods disclosed herein, a surgeoncan initiate dilation of a pathway to the intervertebral disc by usingone of a variety of angles of approach. For example, a surgeon can use alateral, posterolateral, or other angle of approach. The surgeon caninsert a needle into the intervertebral disc, such as a 18G needle. Theneedle can define the pathway to the intervertebral disc. In thisregard, the surgeon can then insert one or more dilators over theneedle.

For example, in one embodiment, the surgeon can insert a first dilatorover the needle and into the intervertebral disc. The surgeon can thenwithdraw the needle completely while the first dilator remains in place.Next, the surgeon can insert a second dilator over the first dilator andinto the intervertebral disc. The second dilator can be configured tohave a larger diameter than the first dilator. Subsequently, the surgeoncan withdraw the first dilator completely while the second dilatorremains in place. As such, the pathway can be dilated in a stepwisemanner to minimize trauma. In some implementations, the first dilatorcan comprise an outer diameter of 3 mm and an inner diameter of 1 mm,and the second dilator can comprise an outer diameter of 6.3 mm and aninner diameter of 3.2 mm. Although the length of the dilators can vary,it is contemplated that the length of the dilators can be approximately210 mm. Further, some implementations can utilize a guidewire having adiameter smaller than the inner diameter of the first dilator.Additionally, the insertion and advancement of the dilators into thedisc opens an initial aperture or hole in the annulus of the disc.

In accordance with some embodiments of the method, after the seconddilator has been placed, the surgeon can insert a first working sleeveover the second dilator. The first working sleeve can be advanced overthe second dilator until it is positioned adjacent to the annulus of theintervertebral disc. It is contemplated that the first working sleevecan be advanced such that a distal end of the first working sleeve ispositioned within the intervertebral disc. However, in some embodiments,the distal end is merely positioned adjacent to or against the annulusof the disc. The first working sleeve can have an inner diameter of 6.35mm and an outer diameter of 9 mm. After the first working sleeve isinserted, the second dilator can be removed.

The first working sleeve is preferably configured to provide asufficiently large interior geometry for advancing tools therein. Forexample, a trephine, crown reamer, and/or punch can be inserted into thefirst working sleeve and used to remove the nucleus of the disc. Thetrackside can have an outer diameter or dimension of approximately 6 mm.Once the nucleus has been removed from the disc, a second working sleevecan be advanced over the first working sleeve and positioned adjacent toor against the annulus of the disc. The first working sleeve can then beremoved. Accordingly, the second working sleeve can be configured with alarger inner and outer diameter than the first working sleeve. Forexample, the second working sleeve can have an inner diameter of 9.2 mmand outer diameter of 10 mm.

In accordance with some embodiments of the method, once the secondworking sleeve is in place, the initial aperture or hole in the annulusof the disc can be enlarged by a drilling procedure. For example, adrill bit can be inserted through the second working sleeve and operateagainst the annulus to create a larger aperture or hole in the annulus.Additionally, the drill bit and can be advanced into the disc in orderto provide an intervertebral spacing approximately equal to the diameterof the drill bit. In this regard, the drill bit can have a diameter ofapproximately 9 mm. Further, the drilling procedure may not only enlargethe aperture or hole in the annulus of the disc, but can also be used toremove portions of the bone. In such embodiments, the drill bit can bebeneficially used to clear a pathway of sufficient size for theplacement or use of other tools and/or the implant. Additionally, thehole may be drilled into the end plates of the vertebrae as well as intothe disc, thereby creating a space for the implant within theintervertebral space wherein the implant may have not otherwise beenable to fit. In some cases, the creation of such a space in theintervertebral space may require not only drilling the disc, but alsothe end plates of the vertebrae.

In some embodiments, the method can further comprise using a rasp tool,such as that illustrated in FIGS. 49 and 50. As shown in these figures,a rasp tool 800 can be configured to define an unexpanded configuration802 shown in FIG. 49 and an expanded configuration 804 shown in FIG. 50.When the tool 800 is initially inserted into the working sleeve, thetool 800 can be positioned in the unexpanded configuration 802. Afterthe tool 800 is advanced into the intervertebral disc, the tool 800 canbe expanded to the expanded configuration 804.

In the embodiment illustrated in FIGS. 49-50, the tool 800 can comprisean elongated body 810 and one or more scraping components 812, 814.FIGS. 49 and 50 illustrate longitudinal cross-sectional views, as wellas end views of the tool 800. As illustrated, the scraping components812, 814 can each comprise an outer surface that is configured to scrapeor create friction against the disc. For example, the outer surfaces canbe generally arcuate and provide an abrasive force when in contact withthe interior portion of the disc. In particular, it is contemplated thatonce the tool 800 is expanded, the scraping components 812, 814 can raspor scrape against the vertebral end plates of the disc from within aninterior cavity formed in the disc. In this manner, the tool 800 canprepare the surfaces of the interior of the disc by removing anyadditional gelatinous nucleus material, as well as smoothing out thegeneral contours of the interior surfaces of the disc. The rasping maythereby prepare the vertebral endplates for fit with the implant as wellas to promote bony fusion between the vertebrae and the implant. Due tothe preparation of the interior surfaces of the disc, the placement anddeployment of the implant will tend to be more effective.

It is contemplated that the tool 800 can comprise an expansion mechanismthat allows the scraping components 812, 814 to move from the unexpandedto the expanded configuration. For example, the full 800 can beconfigured such that the scraping components 812, 814 expand from anouter dimension or height of approximately 9 mm to approximately 13 mm.In this regard, the expansion mechanism can be configured similarly tothe expansion mechanisms of the implants disclosed herein, thedisclosure for which is incorporated here and will not be repeated.

Further, it is contemplated that the scraping components 812, 814 cancomprise one or more surface structures, such as spikes, blades,apertures, etc. that allow the scraping components 812, 814 to not onlyprovide an abrasive force, but that also allowed the scraping components812, 814 to remove material from the disc. In this regard, as in any ofthe implementations of the method, a cleaning tool can be used to removeloosened, scraped, or dislodged disc material. Accordingly, in variousembodiments of the methods disclosed herein, and embodiment of the tool800 can be used to prepare the implant site (the interior cavity of thedisc) to optimize the engagement of the implant with the surfaces of theinterior of the disc (the vertebral end plates).

After the implant site has been prepared, the implant can be advancedthrough the second working sleeve into the disc cavity. Once positioned,the implant can be expanded to its expanded configuration. For example,the implant can be expanded from approximately 9 mm to approximately12.5 mm. The surgeon can adjust the height and position of the implantas required. Additionally, other materials or implants can then beinstalled prior to the removal of the second working sleeve and closureof the implant site.

For example, it is contemplated that bone graft or cement placement maybe performed with this procedure. Further, it is also contemplated thatother methods may be employed for removing the nucleus of the discinstead of using the punch and reamer. Indeed, there are multitudes ofsystems that are designed for removal of the nucleus.

In the figures, the elements have been represented in a schematic way inareas to facilitate conceptual understanding. In particular, the toolsthat can be utilized to implant, actuate the implant, and otherwiseperform the method have been particularly schematic, since these dependnot only on the concrete realization of the implant, but the design andshape of the rest of the instruments being used. Obviously, there arenumerous alternatives to what is shown, particularly as regards todetails of manufacturing.

Although these inventions have been disclosed in the context of certainpreferred embodiments and examples, it will be understood by thoseskilled in the art that the present inventions extend beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the inventions and obvious modifications and equivalentsthereof. In addition, while several variations of the inventions havebeen shown and described in detail, other modifications, which arewithin the scope of these inventions, will be readily apparent to thoseof skill in the art based upon this disclosure. It is also contemplatedthat various combination or sub-combinations of the specific featuresand aspects of the embodiments may be made and still fall within thescope of the inventions. It should be understood that various featuresand aspects of the disclosed embodiments can be combined with orsubstituted for one another in order to form varying modes of thedisclosed inventions. Thus, it is intended that the scope of at leastsome of the present inventions herein disclosed should not be limited bythe particular disclosed embodiments described above.

1. An intervertebral implant for ensuring a minimum distance between twovertebrae, comprising: a pair of opposing body portions each comprisingan external surface and a contact surface that is oriented obliquelyrelative to the external surface, the body portions each comprising atleast one raised structure and at least one gap positioned adjacent tothe raised structure, the raised structure defining a top surface thatforms at least a portion of the contact surface of the body portion, theraised structures of each body portion being insertable into therespective gaps of the other body portion such that the contact surfacesthereof define an internal wedge structure between the body portions;and an expansion component comprising a head portion and a ram member,the expansion component being at least partially insertable between thebody portions with the head portion positioned against the contactsurfaces of the body portions, the ram member being operative to urgethe head portion against the contact surfaces such that movement of thehead portion against the internal wedge structure causes the bodyportions to separate thereby increasing a height of the implant.
 2. Theimplant of claim 1, further comprising a confinement casing to preventthe movement of the head portion of the expansion component in adirection transverse to a longitudinal axis of the implant.
 3. Theimplant of claim 2, wherein the confinement casing comprises a channelconfigured to receive at least a portion of the ram member therein. 4.The implant of claim 3, wherein the confinement casing comprises anelongate body having a lid at an end located distal to the channel and acompartment interposed between the lid and the channel, the compartmentbeing at least partially defined by a pair of sidewalls extendingintermediate the lid and an end of the channel, the compartment beingconfigured to at least partially receive the body portions therein. 5.The implant of claim 3, wherein the channel is threaded and the rammember comprises at least one thread extending along an exterior surfacethereof, the ram member being configured to threadingly engage thechannel of the confinement casing.
 6. The implant of claim 2, whereinthe casing comprises one or more engagement surfaces disposed at aproximal end of the casing, the engagement surfaces being configured toengage with an expansion tool for maintaining a rotational orientationof the implant with respect to at least a portion of the expansion tool.7. The implant of claim 1, wherein the ram member moves in a directionparallel to a longitudinal axis of the implant to urge the head portionagainst the contact surfaces of the body portions.
 8. The implant ofclaim 1, further comprising a recovery element extending between thebody portions.
 9. The implant of claim 8, wherein the recovery elementis a mesh with elastic properties, the recovery element at leastpartially surrounding the body portions.
 10. The implant of claim 8,wherein the recovery element comprises an elastic rubber band.
 11. Theimplant of claim 1, further comprising an expansion limiting system forlimiting the expansion of the implant.
 12. The implant of claim 11,wherein the expansion limiting system comprises a projection formed onone body portion that interferes with an end cap formed on the otherbody portion for limiting relative vertical motion between the bodyportions.
 13. The implant of claim 1, wherein the external surfaces ofthe body portions comprise one or more projections for promotingosseointegration of the surfaces with adjacent vertebrae.
 14. Theimplant of claim 1, wherein the expansion component comprises one ormore engagement structures for engaging with an expansion tool forrotating the expansion component.
 15. The implant of claim 14, whereinthe expansion component comprises a threaded recess for engaging with anexpansion tool for maintaining the expansion component in a given axialposition relative to the tool during rotation of the expansioncomponent.
 16. An intervertebral implant for ensuring a minimum distancebetween two vertebrae, comprising: a first body portion comprising afirst external surface and a first contact surface, the first bodyportion comprising at least one raised structure and at least one gappositioned adjacent to the raised structure; a second body portioncomprising a second external surface and a second contact surface thatis oriented obliquely relative to the first external surface, the secondbody portion comprising at least one raised structure and at least onegap positioned adjacent to the raised structure, the raised structuredefining a top surface that forms at least a portion of the secondcontact surface of the body portion, each raised structure of the firstbody portion being insertable into the respective gap of the second bodyportion and each raised structure of the second body portion beinginsertable into the respective gap of the first body portion such thatthe contact surfaces thereof define an internal wedge structure betweenthe first body portion and the second body portion; an expansioncomponent comprising a head portion and a ram member, the expansioncomponent being at least partially insertable between the first bodyportion and the second body portion with the head portion positionedagainst the first and second contact surfaces, the ram member beingoperative to urge the head portion against the first and second contactsurfaces such that movement of the head portion against the internalwedge structure causes the first body portion to separate from thesecond body portion thereby increasing a height of the implant.
 17. Theimplant of claim 16, wherein the first contact surface of the first bodyportion is oriented obliquely relative to the first external surface.18. The implant of claim 16, wherein the head portion of the expansioncomponent is formed separately from the ram member.
 19. The implant ofclaim 18, wherein the head portion of the expansion component comprisesa generally spherical member.
 20. The implant of claim 16, wherein thehead portion of the expansion component is elastically deformable forproviding a shock absorption capability to the implant.
 21. The implantof claim 20, wherein the head portion is fabricated from one of nylonand Teflon.
 22. The implant of claim 20, wherein the head portioncomprises at least one cavity for enhancing the shock absorptioncapability of the implant.
 23. The implant of claim 16, wherein theexpansion component comprises one or more engagement structures forengaging with an expansion tool for rotating the expansion component.24. The implant of claim 23, wherein the expansion component comprises athreaded recess for engaging with an expansion tool for maintaining theexpansion component in a given axial position relative to the toolduring rotation of the expansion component.
 25. The implant of claim 16,further comprising a confinement casing having a channel and acompartment extending intermediate the channel and a distal end of thecasing, the channel being configured to receive at least a portion ofthe ram member therein, the compartment being at least partially definedby a pair of sidewalls extending intermediate the distal end of thecasing and the channel, the compartment being configured to at leastpartially receive the body portions therein, the confinement casingconfigured to align the body portions in a vertical direction andprevent movement of the expansion component in a direction transverse toa longitudinal axis of the implant.
 26. The implant of claim 25, whereinthe channel is threaded and the ram member comprises at least one threadextending along an exterior surface thereof, the ram member beingconfigured to threadingly engage the channel of the confinement casing.27. The implant of claim 25, wherein the casing comprises one or moreengagement surfaces disposed at a proximal end of the casing, theengagement surfaces being configured to engage with an expansion toolfor maintaining a rotational orientation of the implant with respect toat least a portion of the expansion tool.
 28. An installation tool foran implant, the tool comprising: a handle member having a grippingcomponent and an elongate tubular component extending from the grippingcomponent, the tubular component having a hollow bore and an engagementportion disposed at a distal end thereof, the engagement portion havingone or more protrusions for engaging at least a portion of a proximalend of an intervertebral implant to maintain a rotational orientation ofthe implant relative to the tubular component; a first rotating memberhaving a first knob and an actuation component extending from the firstknob, the actuation component having a hollow bore and a rotationalconnector disposed at a distal end thereof, the actuation componentbeing configured to fit within the hollow bore of the tubular componentof the handle member with the rotational connector being positionedadjacent to the engagement portion of the tubular component for engagingan expansion component of the implant for rotating the expansioncomponent to expand or contract the implant; and a second rotatingmember having a second knob and a retention component extending from thesecond knob, the retention component having a fastening portion disposedat a distal end thereof, the retention component being configured to fitwithin the hollow bore of the actuation component of the first rotatingmember with the retention component being positioned adjacent to therotational connector of the actuation component of the first rotationalmember for engaging the expansion component of the implant formaintaining an axial position of the implant relative to the handlemember during rotation of the expansion component.
 29. The tool of claim28, wherein the engagement portion of the tubular component of thehandle member comprises a pair of protrusions.
 30. The tool of claim 29,wherein the pair of protrusions are disposed on opposing sides of thetubular component with the implant being insertable therebetween. 31.The tool of claim 28, wherein the rotational connector of the actuationcomponent of the first rotating member comprises a pair of linearprotrusions configured to be received in a slot of the expansioncomponent of the implant.
 32. The tool of claim 28, wherein the tubularcomponent of the actuation component and the retention componentcomprise generally cylindrical outer profiles.
 33. The tool of claim 28,wherein the retention component of the second rotating member isconfigured to draw the expansion component of the implant toward theactuation component of the first rotational member as the retentioncomponent engages the ram member.
 34. The tool of claim 33, wherein thefastening portion of the retention component is threaded for threadablyengaging the ram member of the implant.
 35. A method of implanting anexpandable intervertebral implant, comprising: dilating a pathway to anintervertebral disc; removing the nucleus of an intervertebral disc todefine a disc cavity; scraping vertebral end plates from within the disccavity; and deploying an intervertebral implant in the disc cavity. 36.The method of claim 35, wherein the step of dilating comprises:inserting a needle into the intervertebral disc; inserting a firstdilator over the needle into the intervertebral disc; removing theneedle. inserting a second dilator over the first dilator into theintervertebral disc; and removing the first dilator.
 37. The method ofclaim 36, further comprising: inserting a first working sleeve over thesecond dilator to adjacent the intervertebral space; and removing thesecond dilator.
 38. The method of claim 37, further comprising:inserting a second working sleeve over the first working sleeve toadjacent the intervertebral space; and removing the first workingsleeve.
 39. The method of claim 35, wherein the step of removing thenucleus comprises using a trephine tool.
 40. The method of claim 39,wherein the step of removing the nucleus further comprises using a punchtool.
 41. The method of claim 35, further comprising drilling a holeinto the intervertebral disc after dilation.
 42. The method of claim 41,wherein the step of drilling further comprises forming a hole in thevertebral end plates.
 43. The method of claim 35, wherein the scrapingstep comprises inserting a rasp into the intervertebral disc to scrapethe vertebral end plates from within the disc cavity.
 44. The method ofclaim 35, wherein the step of deploying the implant comprises expandingthe implant from approximately 9 mm to approximately 12.5 mm in height.